"The more you publicly commit to an attitude, the better able you are to resist any attempts to change it and this is largely due to those increases in confidence and perceived importance." (blogs.scientificamerica.com)
In this social media society, many people announce their New Year's resolutions on Facebook. Declaring your intentions can make you feel one step closer to your goal. Also, committing publicly to a plan makes you accountable to your family and friends. Others might jump in the boat with you, offering their support. Some might cheer you on privately. Making your plans public is also a good way to connect with like-minded people.
There could be a down side to sharing your resolutions with the public. Such an announcement could invite comments from naysayers, people who are negative or simply jealous of the thought of you accomplishing something that they haven't. I read online that some studies show that when you tell others about your plans, you are less likely to achieve them because in the act of telling, you think you've already performed the task. Don't mistake the act of commitment for progress.
If you prefer not to announce your goals to the world, just tell your best friend. Make periodic reports on your progress. At the very least, if you prefer to tell no one, have a reward system if you stick to your plan and a deterrent system if you stray from your plan. Accountability helps you stay focussed on the task at hand.
For more information, read Done and Done: The Power of Accountability Partnering for Reaching Your Goals by Annette Lyon and Luisa Perkins (2014) at http://www.amazon.com/Done-Power-Accountability-Partnering-Reaching/dp/1497443261.